There is no need for 5 defenders against 1 striker. You'll most likely need more players defending the midfield as well. Against 1 strikers formations with wingers, 3w defenders is all that's necessary. Then a combination of 3 DMC/MC (make sure MC's have blue arrows) should be useful.

The formation of choice for me against the 4-3n-2w-1 is either 3w-1-4-2 or 3w-5-2 flat.

For mentality, i'd go either normal or attacking.

Normal: down the flanks, own half, hard, mixed, zonal,

Attacking: down the flanks, whole pitch, hard, short, zonal, no counter, offsides